High Density Polyethylene (HDPE) Pipe is used in water and sewer pipe installations across the United States. The pipe system is typically joined by thermal fusion or "welding" through the use of "butt-welding" equipment or "electro-fusion" saddles that are often used in trench to connect HDPE pipe segments. The American Water Works Association publishes standards for HDPE pipe used in water mains and transmission lines (AWWA C906) and in service lines (AWWA C901). However, the common HDPE pipe failure modes are not addressed in HDPE pipe manufacturer literature or the reference pipe standards. Listed below are some examples of HDPE pipe failure modes that are frequently encountered in the field. These issues should be considered and addressed proactively in the pipe material selection process, the subsequent design and construction process.